San Francisco International Airport addresses challenges posed by sinking runways and earthquake risks

San Francisco International Airport (SFO), a major hub for international air traffic on the West Coast, handled 47 million passengers in the fiscal year 2022-2023. This marks a 34.9% increase from the previous year. The airport faces challenges, including its runways sinking faster than those at other U.S. airports and its location in an area of high seismic activity.

Researchers from Virginia Tech found that SFO's runways are subsiding at a rate of 10mm annually. "SFO was found to actually have the highest subsidence of the airports that we considered," said Oluwaseyi Dasho. The uneven sinking can lead to runway damage, with Dasho noting, "When you have differential subsidence along the runway, there is a higher risk of damage along the runway."

The airport's vulnerability to earthquakes is another concern. In 2023, a magnitude-3.7 earthquake occurred beneath SFO. The California Earthquake Authority warns of significant earthquake risks in Northern California, estimating nearly a 75% chance of one or more magnitude 6.7 or greater earthquakes striking the region soon.